Additive Engineering Mitigates Residual Stress and Boosts Stability in Wide-Bandgap Perovskite Solar Cells

Materials Futures (IOP Publishing) UK

Overview

This research details an additive engineering approach incorporating N,N-dimethyl-2-aminosulfonylnicotinamide (ANdPy) into perovskite films to mitigate residual stress and enhance carrier dynamics. ANdPy-modified inverted wide-bandgap perovskite solar cells achieved a champion power conversion efficiency of 18.52% alongside improved photo- and thermal stability. This work offers a reliable strategy to facilitate the commercialization of high-efficiency and high-reliability perovskite solar cells.

In Depth

Enhancing Performance and Addressing Stability in Wide-Bandgap Perovskite Solar Cells

Wide-bandgap perovskite solar cells are crucial components that demonstrate high synergistic effects in tandem structures with silicon-based solar cells, significantly boosting overall power conversion efficiency. However, a common challenge in their fabrication is the formation of residual stress within the perovskite film, which compromises the long-term stability and efficiency of the device. This residual stress is known to accelerate the formation of defects and decomposition, particularly under external stresses such as heat and light, leading to performance degradation.

Stress Mitigation and Carrier Dynamics Enhancement via ANdPy Additive

Recent research proposes an “additive engineering” approach involving the introduction of an organic additive, N,N-dimethyl-2-aminosulfonylnicotinamide (ANdPy), into the perovskite precursor solution. This ANdPy additive performs several critical functions during the formation of the perovskite film:

• Effective Residual Stress Reduction: ANdPy contributes to the alleviation of stress during perovskite crystal growth, significantly reducing the residual stress accumulated within the film. This improves the mechanical integrity of the film and enhances its resilience against external stresses.
• Enhanced Carrier Dynamics: ANdPy passivates defects at perovskite grain boundaries, suppressing charge carrier recombination. This leads to a more efficient collection of photogenerated electrons and holes, thereby improving carrier transport efficiency.
• Improved Crystal Quality: The additive also contributes to optimizing the size and orientation of perovskite crystal grains, facilitating the formation of a more uniform and highly crystalline film.

Achieved High Performance and Reliability

ANdPy-modified inverted wide-bandgap perovskite solar cells demonstrated excellent performance:

• Champion Efficiency: A high power conversion efficiency of 18.52% was achieved. This represents excellent performance for wide-bandgap perovskites, especially considering their high potential when used as top cells in tandem structures.
• Improved Photostability: In continuous operation tests under illumination, ANdPy-added devices showed significantly higher stability compared to unmodified devices. The reduction in residual stress and defect passivation is believed to suppress photo-induced degradation.
• Enhanced Thermal Stability: ANdPy-added devices maintained excellent stability even in high-temperature environments, which is crucial for improving durability in practical outdoor conditions.

Technical Significance and Future Outlook

This additive engineering approach, published in ‘Materials Futures,’ offers a reliable strategy for the commercialization of wide-bandgap perovskite solar cells. By simultaneously managing residual stress and defects, it opens a path to achieving both high efficiency and high stability. Future research will likely focus on the mass production of ANdPy, its applicability to other perovskite compositions, and scaling up to large-area devices. This technology is expected to play a significant role in accelerating the widespread adoption of perovskite solar cells as a next-generation renewable energy technology.